Argentina star Lionel Messi shouts in jubilation after scoring a wondrous goal against Bosnia-Herzegovina on Sunday night in Rio de Janeiro.

RIO DE JANEIRO -- It was a win but far from a convincing one. For much of the 62 minutes between Argentina’s first goal and its second, Bosnia was the better side but it was undone first by a moment of ill-fortune and then by a scintillating goal from Lionel Messi.

In the estimation of Alejandro Sabella, the Argentina coach, this was a 6/10 performance with plenty of room for improvement. Messi had had an awkward night. He didn’t play badly as such, but too often he was crowded out, too often forced deep by Bosnia’s pressing.

“It’s difficult to play against Messi or a player like him,” said Bosnia coach Safet Susic. “Initially I thought of man-marking him for 90 minutes, but it’s impossible for anybody and I didn’t want to force a player to be booked once or twice. I gave him some freedom but instructed my team that the closest player to him should approach him, press the ball and not foul him. If he can dribble through he’ll set up his teammates with precision passes so you must stop that.”

The plan had worked to the extent that when Messi fired a free kick over the bar just after the hour, the predominantly Argentinian crowd reacted with boos. Two minutes later, though, he scored a goal of prodigious quality, picking the ball up on the right, darting infield and then dispatching his shot in via the inside of the post.

There were constant glimmers of his genius, but that was the first time one flickered into something tangible, and it was surely no coincidence that the space opened for him after the introduction of Gonzalo Higuain and the return to the 4-3-3 Argentina had used through the majority of the qualifying campaign.

Sabella’s switch to 5-3-2 was mystifying – all the more so when he evaded questions about it at his pre-match press-conference before saying he was contemplating the change for reasons he didn’t want to talk about publicly. Without Higuain on the pitch, Messi too often was forced too deep, which meant that even if he did manage to beat the first or the second defender, he was never in a position to inflict damage on Bosnia.

“In the first half we gave up possession to Bosnia,” he said, “and so I was too deep: I was alone and Kun [Aguero] was alone. It was very difficult.”

That suggested that there was no basis to the rumors that Messi had been the cause of the tactical switch, but Sabella was again vague as to his thinking, saying merely that he had wanted to “complicate” things for Bosnia. Once Argentina had gone ahead through Sead Kolasinac’s own-goal – the ball cannoning in off his legs after Marcos Rojo had flicked on a Messi free-kick – Bosnia looked the more threatening, although the only clear chance it created was Senad Lulic’s header shortly before halftime that was saved low to his left by Sergio Romero.

The change of shape, though, created more space for Messi, and it was that he exploited to score only his second World Cup goal, just shy of eight years to the day after he got his first in the 6-0 win over Serbia-Montenegro.

“We like [the 4-3-3] better because when you go forward you have more possibilities of passing the ball and scoring,” Messi said. “We strikers and forwards are favored by this formation.”

Yet Argentina was still not entirely convincing, the momentum Bosnia had built up in the first half carrying it through the second. Vedad Ibisevic’s late goal caused a few moments of anxiety, but Argentina realistically never lost control.

“It’s important to start off with the three points and start winning,” said Messi. “We do have things to improve. But it’s difficult the first game with the anxiety, and the nerves. The best thing is the result. I believe it was a great second half. We had the ball, we created opportunities and that’s what we have to do. We have to continue doing what we did in the second half.”

Great might be stretching it, but it was certainly much improved, and, with Higuain’s fitness improving, it’s safe to assume the 4-3-3 will become the default formation again. In the second half, Sabella explained, there was “more support around Messi. Once he received the ball, there was better follow-up play.”

Messi dominated the post-match discussion, which says much both for his centrality to Argentina, and to the general desire for him to produce something like his best for at the tournament. In that regard, it was probably significant that he scored, which at least eases some of the scrutiny after his disappointing 2010 – albeit that he played reasonably well in the circumstances.

“Messi is the best player in the world,” said Sabella. “It’s not that he needs a lot, but beyond that there’s always a context and it can empower him a bit more. When he receives a push from his colleagues that no doubt empowers him even more.”